Temperature-dependent ferroelectric properties of near stoichiometric lithium niobate single crystal

Abstract

The temperature dependent ferroelectric hysteresis properties of stoichiometric lithium niobate single crystals have been studied in this article. It is found that remnant polarization (Pr) and the coercive field (Ec) increase monotonically with increasing electric field at 293 K, and the Pr at 76 K is smaller than that at 293 K due to less switchable domains can be activated at low temperature, whereas the Ec at 76 K is larger than that at 293 K due to the trapped oxygen vacancy cannot be detrapped easily at low temperature. However, both the Pr and Ec increase when the temperature decreases from 293 to 247 K, then decrease with further decreasing temperature to 76 K. The pinning of the switched domains induces the increase of Pr and the deepening and widening of the domain wall-defect interaction potential well makes the activated domains difficult to be back-switched leads to the increase of Ec when the temperature decreases from 293 to 247 K, while less domains will be activated in the domain switching process induces the decrease of Pr and the frozen of domains with higher activation energy is the cause of Ec decreasing from 247 to 76 K.